Protein powder

What is protein powder and what types are there?

Protein powder is protein separated from a food source and concentrated. According to the ISSN’s explanation, in milk protein products the proteins are first separated from lactose and fat; casein is precipitated with acid, the part remaining in the liquid becomes whey, and it is then purified by filtration. Products in which 29–80% of dry weight is protein are counted as concentrates, and those containing more than 90% protein as isolates; concentrates with 70–80% protein are generally used in sports products. Hydrolysates are forms in which the protein has been broken down in advance into small peptides with digestive enzymes. ^[1]

The main types are as follows:

• Whey: Found as concentrate, isolate and hydrolysate; it is the most researched athlete protein. Details are on the Whey protein page.
• Casein: The slowly digested protein of milk. Studies of nighttime use are described on the timing page.
• Egg protein: The ISSN states that whole (unbroken) protein sources such as egg, whey, casein, beef, soy and even whole milk can produce an anabolic response similar to or greater than free amino acids when an equal amount of essential amino acids is given. ^[1]
• Plant proteins: The ISSN 2017 states that research examining the effect of plant sources other than soy, such as pea, rice and hemp, on exercise performance and training adaptation is limited. ^[1]

Which legislation these products fall under in Türkiye is explained separately below.

How much protein is needed per day?

Reference values vary by organization, and all are for total protein from foods; the amount from powder is only a part of this total.

The US RDA is set two standard deviations above the EAR, the lowest continuous intake that achieves nitrogen balance (zero balance). ^[4] EFSA likewise reaches the PRI of 0.83 g/kg/day from the average requirement of 0.66 g/kg/day using the 97.5th percentile, and states that this value applies both to high-quality protein and to protein in mixed diets. EFSA also evaluated various health outcomes that may be associated with protein intake, but reported that the data were insufficient to set a reference value based on them. ^[3]

The ISSN’s range of 1.4–2.0 g/kg/day is not an RDA; it is a position stand for healthy people who exercise. The same document says that higher intakes (2.3–3.1 g/kg/day) may be needed to preserve lean mass in people doing resistance training during calorie restriction. ^[1] This guide does not give a personal amount; the calculation logic is on the how to use page.

Is protein powder needed, or is food not enough?

The ISSN states that it is possible for physically active people to meet their daily protein requirement with whole foods, and that supplementation is a practical way to provide adequate protein quality and amount with fewer calories, particularly for athletes doing high-volume training. ^[1] That is, the powder is not a superior source that replaces foods but a form that conveniently completes the requirement. For a person getting enough protein from food, an additional benefit of the powder has not been proven; the additional gains in the meta-analysis were also seen only until total protein intake reached a certain level (below).

How much does protein powder help muscle and strength?

The 2018 meta-analysis by Morton and colleagues compiled randomized trials lasting at least 6 weeks that included resistance training and protein supplementation: 49 trials, 1,863 participants, healthy adults. Protein supplementation gave an additional average gain of 0.30 kg (95% CI 0.09–0.52) in lean mass and 2.49 kg (0.64–4.33) in one-repetition maximum strength. Muscle fiber cross-sectional area and mid-thigh cross-sectional area also increased. ^[2]

Two limitations stood out in the same study. The lean mass effect of supplementation decreased with age (−0.01 kg per year) and was more pronounced in those with resistance training experience (0.75 kg). When total protein intake exceeded about 1.62 g/kg/day, no additional gain in lean mass was seen. ^[2] That is, the size of the effect is small, and it is not “the more the better.”

A note is needed for this study: the correction published in 2020 did not change the numerical results; it added the information that one of the authors is on the advisory board of a company that produces sports supplements. In the original article, one author also reported research support, travel expenses, and speaker honoraria from a US dairy-sector body that supported some of the trials analyzed. ^[2]

Detailed guideWhen to take protein powder? Anabolic window, meal distribution and nighttime casein→

What does protein provide while losing weight?

The meta-analysis by Wycherley and colleagues compared a high-protein pattern with a standard-protein pattern in energy-restricted, low-fat diets: 24 trials, 1,063 people, mean duration 12.1 weeks. The high-protein diet gave −0.79 kg (−1.50 to −0.08) in body weight, −0.87 kg (−1.26 to −0.48) in fat mass, and a 0.43 kg (0.09–0.78) smaller loss of lean mass. Greater satiety was reported in 3 of the 5 trials assessed. ^[8]

Two limitations matter. The difference is small and short-term; moreover, the comparison examines the protein proportion of the diet, not protein powder. It cannot be said from these data that the powder by itself causes weight loss.

Is protein need different in older adults?

The position paper of the PROT-AGE study group recommends that, to preserve lean body mass and function in people over 65, mean daily intake be at least 1.0–1.2 g/kg; ≥1.2 g/kg/day is stated for those who exercise and are active, and 1.2–1.5 g/kg/day for most older adults with acute or chronic disease. People with severe kidney disease (eGFR below 30 mL/min/1.73 m²) who are not on dialysis are an exception; these people may have to limit their protein intake. The same document also says that protein quality, timing and other supplements may be important, but that evidence is not yet sufficient for a specific recommendation. ^[7]

Whether these recommendations are to be met with foods or powder is not the subject of the document. In the Morton meta-analysis, the lean mass effect of protein supplementation decreased with age. ^[2] The evidence grade for powder use in older adults is therefore given as C.

Does protein powder harm the kidneys?

The answer depends on kidney status.

Adults without kidney disease. The meta-analysis by Devries and colleagues compiled randomized trials lasting longer than 4 days that compared glomerular filtration rate (GFR) between high-protein (≥1.5 g/kg, ≥20% of energy or ≥100 g/day) and normal- or low-protein diets: 40 articles were selected for full text, and 28 entered the analysis (1,358 participants). Post-intervention GFR was trivially higher in the high-protein group (SMD 0.19; 95% CI 0.07–0.31); the change in GFR from baseline did not differ between groups (SMD 0.11; 95% CI −0.05 to 0.27). The authors state that the risk of selection bias in the included studies is unclear; in their own GRADE tables, certainty of evidence is graded “very low” for change in GFR and “low” for post-intervention GFR. One of the authors reported receiving research funding and speaking fees from dairy and beef industry organizations. ^[5]

Chronic kidney disease (CKD). The KDIGO 2024 guideline recommends maintaining a protein intake of 0.8 g/kg/day in adults at stages G3–G5 (weak recommendation, low certainty: 2C) and lists avoiding high protein intake (>1.3 g/kg/day) in CKD at risk of progression as a practice point. The same guideline states that protein should not be restricted in children with CKD because of the risk of impaired growth, and that higher targets may be considered in older adults with frailty and sarcopenia. ^[6]

Open the Deep view for details → Detailed guideProtein powder harms: kidney, liver, bone, acne and who should stay away→

Is there a link between protein powder and acne?

The only source on acne is a small case series reported from Türkiye: 6 healthy adolescent boys who developed acne only on the trunk had used whey protein supplementation for bodybuilding. The authors present this as the first observation indicating the trunk location of acne; the study has no control group, the number of cases is very small, and it does not show causality. ^[9] The evidence is therefore at grade D.

How is protein powder regulated in Türkiye?

Two separate Turkish Food Codex (Türk Gıda Kodeksi) communiqués are relevant in Türkiye. The Communiqué on Food Supplements (Takviye Edici Gıdalar Tebliği, 2013/49) defines as food supplements products of concentrates or extracts of nutrients such as vitamins, minerals, protein and amino acids prepared in forms such as capsules, tablets and powder sachets, with a set daily intake dose. ^[11]

The Communiqué on Sports Foods (Sporcu Gıdaları Tebliği, 2003/42) separately defines products containing protein and protein components “formulated to maintain protein balance during periods of intense physical activity” as sports foods. According to the original text, in protein concentrates the proportion of protein derived from egg, milk, meat or soy in the dry matter must be at least 70%, and substances on the International Olympic Committee–World Anti-Doping Agency prohibited substances list cannot be present in products within the scope of this communiqué. ^[10]

Which communiqué a product is sold under is understood from its label; this guide does not recommend a product. Problems of label accuracy and heavy metal and prohibited substance contamination are described, with sources, on the harms page.

For whom is physician assessment needed with protein powder?

People diagnosed with kidney disease, those in the pre-dialysis period, and severe kidney disease in older adults (the PROT-AGE exception above) are the first group; in these people the protein target is determined by the physician and dietitian. ^[6] Data on the benefit and safety of protein powder in children and adolescents are limited; the acne case series in adolescent boys is described above. Safety data specific to protein powder in pregnancy and breastfeeding are also limited; the Communiqué on Food Supplements makes mandatory a warning on the label of these products stating that a physician should be consulted in case of pregnancy, breastfeeding, illness or medication use. ^[11] For athletes subject to doping control, the risk of product contamination is a separate topic and is described on the harms page.

The food supplement definition uses the phrase “for the purpose of supplementing normal nutrition”; that is, the product is not a treatment but a nutritional supplement. ^[11]

Detailed guideWhey protein: concentrate, isolate, hydrolysate and reading the label→ Detailed guideHow is protein powder used? Calculating need, mixing and label check→

For another sports supplement used together with resistance training, the creatine page can be consulted, and for the bone health and calcium connection, the calcium guide. This guide does not recommend a personal amount.